“Pacritinib has been well tolerated and has shown activity in alleviating MF-associated splenomegaly and constitutional symptoms with lack of myelosuppression. This is critical to MF patients with impaired hematopoiesis,” said Tamar Howson, interim CEO and board member of S*BIO. “Pracinostat showed activity in reducing spleen and/or liver size in MF patients.”

Pacritinib showed promising efficacy in alleviating MF-associated splenomegaly and constitutional symptoms at a dose that induces minimal myelosuppression. Once-daily dosing is well tolerated, with manageable GI toxicity as the main side effect. Given the lack of myelosuppression with pacritinib, this JAK2 inhibitor is of particular importance for MF patients with impaired hematopoiesis, especially those patients with thrombocytopenia and anemia.

Therapy with the Histone Deacetylase Inhibitor Pracinostat (SB939) for Patients with Myelofibrosis

Pracinostat demonstrated activity as a single agent in patients with MF. Most responses consisted of reductions in spleen and/or liver size with minimal activity on anemia.

Pacritinib is a small molecule JAK2-selective kinase inhibitor, which has demonstrated high potency in preclinical models against both the wild type JAK2 kinase and the JAK2 kinase with the V617F mutation. The V617F mutation is found in high frequencies in myeloproliferative disorders such as MF. It is estimated that approximately 50% of patients with MF possess the JAK2 mutation.

Pracinostat is an inhibitor of a group of enzymes called histone deacetylases (HDAC) that is implicated in tumourigenesis. Pracinostat is designed to be a “best-in-class” HDAC inhibitor.

About S*BIO Pte Ltd

S*BIO is a privately-held biotech company focused on the clinical development of novel targeted small molecule drugs for the treatment of cancer with leading programs including kinases and histone deacetylases (HDAC). Pacritinib, or SB1518, S*BIO’s potent and orally-active JAK2 inhibitor, entered the clinic in 2008 and has completed Phase 2 trials for MF. It has received orphan drug designation from the U.S. and the E.U. regulatory authorities. S*BIO’s lead HDAC inhibitor, pracinostat (SB939), is currently in Phase 2 trials. S*BIO’s SB1317, a novel multikinase inhibitor, is in Phase 1 trials and
under a worldwide exclusive license with Tragara Pharmaceuticals, Inc. for its development and commercialization.

S*BIO has strong links with a network of medical oncologists in Asia Pacific and its investors include Bio*One Capital a subsidiary of EDBI (EDB Investments), Aravis Ventures, Mitsui Ventures, Novartis
Bioventures and other international funds. More information about S*BIO can be found at www.sbio.com